循环饱和作用下长石花岗岩劣化机理研究

The Guangdong-Hong Kong-Macao Greater Bay Area is located on the northern edge of the South China Sea.The stability of coastal dam is the first important defense line for the safety of coastal buildings and residents.The tidal action will cause damage to the coastal dam,posing a potential threat to the safety of the coastal building and residents.As the dam foundation rock mass along the coast of Zhuhai,Feldspar granite has a lower stength than quartz granite's.There are less mechanical studies,and the deterioration mechanism of feldspar granite under cyclic saturation is still insufficient.In this paper,we selected Zhuhai feldspar granite as the research object,discussed the influence of cyclic saturation on dam stability and clarified the deterioration mechanism of dam rock caused by tidal action.The mechanism of granite degradation induced by cyclic saturation was investigated from multi-scale by means of digital image correlation method and acoustic emission monitoring technology.The preliminary experimental results show that the cyclic saturation weaken the mechanical properties of granite,and the number of cyclic saturation shows a negative correlation with the elastic modulus and mechanical strength.In terms of microstructure,cyclic saturation destroy the intercrystalline cement structure.The crystal grains deformed imhomogeneously under cyclic saturation,where the deformation of feldspar crystal is obviously larger than that of quartz crystal and biotite crystal.we will quantitatively characterize the grain-scale deformation and interaction between different grains,and probe the relation from micro deformation and macro deterioration mechanism in the future,which will be useful to stability assessment of coastal dam.